Lathes are used in the art of carving wood pieces by spinning wood pieces at sufficient speed and applying a sharp instrument to the wood piece for patterning or carving. The lathe typically includes a flat horizontal bed with rails mounted on the bed. Typically a support block or tool rest for supporting a cutting tool is slidably mounted on the bed rails. The cutting tool may be manually applied to the face of a wood block, using the support block or tool rest as a fulcrum to manipulate the tool upon the wood. When cutting tools are manually applied, accurate, consistent patterning of the wood piece is difficult to achieve. Cutting tools have also been secured upon the lead edge of a cutting member which is slidably or rotatably secured to the support block or tool rest. Sliding the support block along the bed rails to a position adjacent to the wood piece allows for selective application of the cutting piece by rotating or sliding the cutting member upon the sliding block.
The use of a lathe machine to construct bowls is known. A bowl may be constructed using a lathe by manually applying a cutting instrument to carve out an interior portion of the wood piece. Typically the cutting instrument is rested on a tool rest or support block and the tool rest or support block acts as a fulcrum for the tool. Manual application of the tool makes it difficult to achieve consistency between work pieces. To allow for more consistent application when constructing a bowl using a lathe machine, a cutting tool may be rotatably mounted via a post upon a support block slidable on the bed rails. The support block is slidably positioned and secured adjacent to the wood piece. A cutting member having a cutting piece at its lead end extends from the post. The cutting member may then be rotated on a fixed path into contact with the wood piece creating a fixed radius cored bowl. To bore out bowls of selectively various sizes, the cutting members have consisted of a series of blades of varying curves and lengths. Using such fixed path cutting machines makes the desired consistency between bowls easier to achieve.
Known cutting pieces secured at the lead ends of cutting members used to cut wood using a lathe have been known to be susceptible to catching in the wood, causing excess vibration and excessive rotational forces caused by the spinning wood piece. These factors in turn tend to cause excess wear on the lathe machine and damage and distortion of the cutting member, posts and various components of the lathe machine.
Cutting pieces are known to have a substantially flat or rounded upper side extending from the lead edge of a cutting member to a cutting edge extending substantially transversely across the lead edge of the piece. Typically, a substantially vertical and/or slightly angled lead face extends downwardly from the transverse cutting edge. The transverse cutting edge is applied to the wood block attached to the lathe. Such pieces are susceptible to catching and tend to create significant rotational force on the cutting edge as it is applied to the rotating wood block.
Cutting pieces are also disclosed having a spear cutting point for application to the wood block. Although such a spear point will reduce the likelihood of catching, they are known to cause significant vibration to the machine.
Tool pitch is the rotational pulling force on the cutting edge of the tool caused as it is applied to the rotating block of wood. As the cutting edge extends into the wood and away from the support block or tool support, tool pitching increases.
In order to reduce the amount of pitch on the lead edge of the cutting member, various types of supports are known to be positionable below the lead edge of the cutting tool as it is applied to the wood block. Such a support surface supports the cutting member as it is initially inserted into the wood. Because the support sits directly below or close to the lead edge of the cutting member, lead edge pitching is reduced.
Once the lead edge of cutting tool has been inserted substantially into the wood block, it becomes more susceptible to pitching because there is no support directly below it. As the lead edge of the cutting member enters the wood piece when cutting a groove, supports disclosed in the prior art are not capable of following the lead edge of the cutting tool into the wood. Thus, such supports are not capable of preventing pitching as the tool head is advanced into the block of wood. The problem of pitching of the lead edge of the cutting tool becomes greater when using longer cutting members curved for bowls of larger radius, since they are separated by more distance from the tool support as they enter into the wood piece.
There is a need for an improved cutting piece or attachment for cutting wood using a lathe and there is a need for an improved system for forming or coring bowls using a lathe.